MOSCOW, April 11. /TASS/. US reconnaissance plane RC-135U was heading towards Russia’s state border and Russian Su-27 fighter jet made it change its course, the Russian Defense Ministry’s official spokesman told reporters on Saturday.

The incident occurred on April 7 when the Russian air defense forces on duty found an unknown air target over the Baltic sea that was moving towards the Russian state border, Gen. Maj. Igor Konashenkov said.

The Su-27 fighter jet approached the unknown plane and flew around it several times and identified it as the RC-135U reconnaissance plane of the US Air Force and reported to the command about the incident, he said.

The US plane changed its course and flew away from the Russian border, Konashenkov said. He stressed that during the spy plane’s flight the transponder was turned off.

"No extraordinary situations occurred when the [fighter jet] flew around the US reconnaissance plane," Konashenkov said.

"As for the assessment of professional qualities of our pilots, this is up to the Russian command. And US reconnaissance planes can perform routine flights only along the US borders," he added.

The Pentagon earlier claimed that the RC-135U was performing a routine flight in the international airspace on April 7 when it was intercepted by Russia’s Su-27 in an "unsafe and unprofessional manner."